Showing papers by "Marios Sophocleous published in 2009"

Groundwater resources, climate and vulnerability

Abstract: Groundwater is an important component of the freshwater system and its role is becoming even more prominent as the more accessible surface water resources become increasingly exploited to support increasing populations and development. Yet despite its significance, there has been comparatively little research conducted on groundwater relative to surface water resources, particularly in the context of climate change impact assessment. This focus issue has therefore been assembled to expand upon the currently limited knowledge of groundwater systems and their links with climate. Many of the papers included here explore the interrelated issues of groundwater resources, climate-related changes and vulnerabilities at a regional scale in different continents and globally. See the PDF for the full text of the editorial. Focus on Groundwater Resources, Climate and Vulnerability Contents Groundwater: from mystery to management T N Narasimhan Simulated response of groundwater to predicted recharge in a semi-arid region using a scenario of modelled climate change M W Toews and D M Allen Long-term climatic change and sustainable ground water resources management Hugo A Loaiciga Climate change and groundwater: India's opportunities for mitigation and adaptation Tushaar Shah Vulnerability to the impact of climate change on renewable groundwater resources: a global-scale assessment Petra Doll Influence of soil heterogeneity on evapotranspiration under shallow water table conditions: transient, stochastic simulations Stefan J Kollet Nutrient cycling and N2O emissions in a changing climate: the subsurface water system role Georgia Destouni and Amelie Darracq Rainfall intensity and groundwater recharge: empirical evidence from the Upper Nile Basin M Owor, R G Taylor, C Tindimugaya and D Mwesigwa

Soil Nitrogen Balance under Wastewater Management : Field Measurements and Simulation Results

Abstract: The use of treated wastewater for irrigation of crops could result in high nitrate-nitrogen (NO 3 -N) concentrations in the vadose zone and ground water. The goal of this 2-yr field-monitoring study in the deep silty clay loam soils south of Dodge City, Kansas, was to assess how and under what circumstances N from the secondary-treated, wastewater-irrigated corn reached the deep (20-45 m) water table of the underlying High Plains aquifer and what could be done to minimize this problem. We collected 15.2-m-deep soil cores for characterization of physical and chemical properties; installed neutron probe access tubes to measure soil-water content and suction lysimeters to sample soil water periodically; sampled monitoring, irrigation, and domestic wells in the area; and obtained climatic, crop, irrigation, and N application rate records for two wastewater-irrigated study sites. These data and additional information were used to run the Root Zone Water Quality Model to identify key parameters and processes that influence N losses in the study area. We demonstrated that NO 3 -N transport processes result in significant accumulations of N in the vadose zone and that NO 3 -N in the underlying ground water is increasing with time. Root Zone Water Quality Model simulations for two wastewater-irrigated study sites indicated that reducing levels of corn N fertilization by more than half to 170 kg ha -1 substantially increases N-use efficiency and achieves near-maximum crop yield. Combining such measures with a crop rotation that includes alfalfa should further reduce the accumulation and downward movement of NO 3 -N in the soil profile.